/Engine/Plugins/Experimental/MeshModelingToolsetExp/Source/MeshModelingToolsExp/Public/MeshGroupPaintTool.h
Allow the Tool to do any custom screen space drawing
virtual void DrawHUD ( [FCanvas](API\Runtime\Engine\FCanvas) * Canvas, [IToolsContextRenderAPI](API\Runtime\InteractiveToolsFramework\IToolsContextRenderAPI) * RenderAPI )